Observatory Employs New Process in Gemini Mirrors

Photonics SpectraSep 1998AlumiPlate Inc. of Minneapolis, in collaboration with the National Optical Astronomy Observatory and II-VI Inc. of Saxonburg, Pa., has developed a diamond-turning process that yields the high-quality mirrors necessary for the near-IR spectrograph in the Gemini 8-m telescope project.

In producing high-surface-quality metal mirrors, engineers typically use electroless nickel to plate the mirrors, but bending of the mirror surface can occur when the temperature changes. AlumiPlate says that the new diamond-turning process decreases the risk of thermally induced distortions, while also reducing the chance of surface pitting or breakage of diamond-cutting tools.
A nonprofit consortium of 27 US institutions and four international affiliates manages the Gemini project. The observatory is headquartered at the University of Hawaii in Hilo.

The scientific observation of celestial radiation that has reached the vicinity of Earth, and the interpretation of these observations to determine the characteristics of the extraterrestrial bodies and phenomena that have emitted the radiation.